考虑渗沥液作用的垃圾填埋体组合破坏稳定分析

现代垃圾填埋场基本采用复合衬里结构，破坏面背坡沿垃圾填埋体内部、底坡沿衬里界面的平移滑动破坏形式成为垃圾填埋体可能的组合破坏形式之一。为了在目前该破坏形式稳定性计算方法的基础上考虑渗沥液的影响，假设穿过垃圾填埋体内部的破坏面为主动破坏面，利用刚体极限平衡分析方法，同时分类讨论渗沥液水位相对于特定界面的不同位置关系，得出每种情况下的计算方法。计算分析结果表明：渗沥液水位升高时，垃圾填埋体的破坏由沿衬里界面的平移滑动破坏演变为穿过垃圾填埋体内部和底部衬里的组合破坏；实际工程算例中，发生破坏失稳正是由于渗沥液水位过高引起的。

Stability analysis of composite failure of waste dumps considering effect of leachate

Composite liners are commonly used in modern landfills. The translational slide failure modes, in which the back slope of the failure surface slides along the inside of waste dump and the bottom slope slides along the liner interface, may become one of the composite failure modes. In this study, we considered the effects of leachate based on the methods for stability calculation of such failure modes. We assumed that the failure surface through the inside of the waste dump was an active failure surface. Then, we used the limit equilibrium analysis method and discussed different positional relationships between leachate levels and specific interfaces, in order to obtain the calculation methods for different situations. The results of analysis and calculation show that, when the leachate water levels rose, the failures of waste dumps changed from translational slides along the liner interface to composite failures through the inside of waste dumps and the bottom liner. In practical engineering examples, the failure and instability occurred precisely because the leachate water level was too high.